Which One of the Following Is the Best Example of Dynamic

Which one of the following is the best example of dynamic assessment?

A) Mr.Thiessen asks Macy to show him how to use a microscope properly.
B) Ms.Yoo asks her students to work in groups of three to write a paper evaluating the effectiveness of the United States' attacks on Iraq in 1990.
C) Ms.Vincent gives her students twenty; she then gives twenty more difficult questions to students who have done very well on the first set, as a way of assessing the upper limits of their knowledge.
D) Mr.Warren observes and records how Erica's logical thinking changes over time as she experiments with a pendulum.